Revert 114494 - Remove BindStateHolder and have Bind() return a Callback<> object directly.

This removes some complexity and also fixes a bug where if you call Bind() with the result of Bind(), the resulting Callback would only be valid during the first call.  Ouch.

BUG=none
TEST=new unittests


Review URL: http://codereview.chromium.org/8738001

TBR=ajwong@chromium.org
Review URL: http://codereview.chromium.org/8914022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114495 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 5 insertions, 7 deletions

diff --git a/base/debug/trace_event.cc b/base/debug/trace_event.cc
index 61d3daf..5be1557 100644
--- a/base/debug/trace_event.cc
+++ b/base/debug/trace_event.cc
@@ -296,8 +296,7 @@ TraceResultBuffer::TraceResultBuffer() : append_comma_(false) {
 TraceResultBuffer::~TraceResultBuffer() {
 }
 
-void TraceResultBuffer::SetOutputCallback(
-    const OutputCallback& json_chunk_callback) {
+void TraceResultBuffer::SetOutputCallback(OutputCallback json_chunk_callback) {
   output_callback_ = json_chunk_callback;
 }
 
diff --git a/base/debug/trace_event.h b/base/debug/trace_event.h
index 621d6f06..ab56dfc 100644
--- a/base/debug/trace_event.h
+++ b/base/debug/trace_event.h
@@ -751,7 +751,7 @@ class BASE_EXPORT TraceResultBuffer {
   // JSON output and during AddFragment and Finish with following JSON output
   // chunks. The callback target must live past the last calls to
   // TraceResultBuffer::Start/AddFragment/Finish.
-  void SetOutputCallback(const OutputCallback& json_chunk_callback);
+  void SetOutputCallback(OutputCallback json_chunk_callback);
 
   // Start JSON output. This resets all internal state, so you can reuse
   // the TraceResultBuffer by calling Start.
@@ -818,8 +818,7 @@ class BASE_EXPORT TraceLog {
   // undefined. Use TraceResultBuffer to convert one or more trace strings to
   // JSON.
   typedef RefCountedData<std::string> RefCountedString;
-  typedef base::Callback<void(const scoped_refptr<RefCountedString>&)>
-      OutputCallback;
+  typedef base::Callback<void(scoped_refptr<RefCountedString>)> OutputCallback;
   void SetOutputCallback(const OutputCallback& cb);
 
   // The trace buffer does not flush dynamically, so when it fills up,
diff --git a/base/debug/trace_event_unittest.cc b/base/debug/trace_event_unittest.cc
index 913a9d3..0ff986a 100644
--- a/base/debug/trace_event_unittest.cc
+++ b/base/debug/trace_event_unittest.cc
@@ -42,7 +42,7 @@ class TraceEventTestFixture : public testing::Test {
   // up multiple times when testing AtExit. Use ManualTestSetUp for this.
   void ManualTestSetUp();
   void OnTraceDataCollected(
-      const scoped_refptr<TraceLog::RefCountedString>& events_str);
+      scoped_refptr<TraceLog::RefCountedString> events_str);
   DictionaryValue* FindMatchingTraceEntry(const JsonKeyValue* key_values);
   DictionaryValue* FindNamePhase(const char* name, const char* phase);
   DictionaryValue* FindNamePhaseKeyValue(const char* name,
@@ -89,7 +89,7 @@ void TraceEventTestFixture::ManualTestSetUp() {
 }
 
 void TraceEventTestFixture::OnTraceDataCollected(
-    const scoped_refptr<TraceLog::RefCountedString>& events_str) {
+    scoped_refptr<TraceLog::RefCountedString> events_str) {
   AutoLock lock(lock_);
   json_output_.json_output.clear();
   trace_buffer_.Start();